const m=['a'..'z','A'..'Z'];
var s:string;
    l,c:integer;
    f,g:text;
    ok:boolean;
begin
assign(f,'text.in');reset(f);
assign(g,'text.out');rewrite(g);
readln(f,s);
c:=0;l:=0;
while s<>'' do begin
      ok:=false;
      while s[1] in m do begin
            ok:=true;
            inc(l);
            delete(s,1,1);
      end;
      if ok then inc(c)
            else delete(s,1,1);
end;
writeln(g,l/c:5:0);
close(g);
end.